1. Field of the Invention
This invention relates to a method of manufacturing a head actuator assembly used in a disk device and a method of manufacturing the disk device.
2. Description of the Related Art
In recent years, disk devices, such as magnetic disk devices, and optical disk devices, have been widely used as external recording devices of computers and image recording devices. A magnetic disk device as an example of a disk device comprises magnetic disks located in a case, a spindle motor that supports and rotates the disks, magnetic heads for writing and reading information to and from the disks, and a head actuator assembly that supports the heads for movement with respect to the disks.
Usually, the head actuator assembly has a slider formed having a magnetic head, a suspension that supports the slider, and an arm that supports the suspension. A wiring pattern is fixed on the suspension and the arm, the slider is fixed on the wiring pattern, and the magnetic head is connected electrically to the wiring pattern.
The arm of the head actuator assembly is rotatably supported by a bearing assembly. A voice coil that constitutes a voice coil motor is mounted on the other end of the arm. The magnetic head can be moved to any desired position on a magnetic disk by rotating the head actuator assembly by the voice coil motor.
In the magnetic disk device described above, the magnetic head flies at a very low height above a surface of the magnetic disk as it records and reproduces information. Thus, very small foreign matter must be prevented from getting into the device, so that the device must be assembled in a high-performance clean room. Generally, therefore, the head actuator assembly is also assembled in the clean room. Recently prevailing magnetic heads have an ultrathin-film structure, so that their electrostatic resistance is very low, and they are expected to be assembled in an environment that is backed by highly sophisticated measures to counter static electricity.
In general, as is described in Jpn. Pat. Appln. KOKAI Publication No. 2002-269714, for example, a magnetic head is temporarily assembled as a head-gimbals assembly (hereinafter referred to as an HGA), a peculiar component, attached to a suspension, and is subjected to inspection thereafter. In assembly processes, the HGA is attached to an arm that is supported by a bearing assembly, and a voice coil is attached to a mechanical part including an arm. A head actuator assembly is assembled by further connecting the HGA electrically to a flexible board that has a control circuit.
All these assembly processes are performed in a clean room. Also proposed is a configuration such that a suspension and an arm are formed integrally with each other or a head stack is formed by stacking in layers suspensions that are previously fixed to arms, individually.
If the head actuator assembly is assembled entirely in the clean room in this manner, the clean room should be large, and the assembly conditions strict. In assembling a suspension assembly, moreover, signal wires that extend from the magnetic head and overlies the suspension are connected to the flexible circuit board having the control circuit by soldering or the like. Possibly, the magnetic head may undergo dielectric breakdown caused by fine static electricity during connection work or its preceding assembly operations.